That's a good question and one that also applies to Ram Concept or Ram Foundation. We usually recommend an analysis of the factored load combinations to yield the strength level concrete demands. It is possible that these factored load combinations could result in an instability while the service combos are all stable, but those cases tend to be the ones where users are "pushing the envelope" anyway, so making the footing larger to stabilize factored load combinations is reasonable.
I know a few users who prefer to amplify the service forces as you suggest, and that seems fine so long as the load factor is conservative.